Set this environment variable to use a particular directory, other than the
default, for Jupyter config files.

Besides the user config directory mentioned above, Jupyter has a search
path of additional locations from which a config file will be loaded. Here’s a
table of the locations to be searched, in order of preference:

Jupyter uses a search path to find installable data files, such as
kernelspecs and notebook extensions. When searching for
a resource, the code will search the search path starting at the first
directory until it finds where the resource is contained.

Each category of file is in a subdirectory of each directory of the
search path. For example, kernel specs are in kernels subdirectories.

Set this environment variable to provide extra directories for the data
search path. JUPYTER_PATH should contain a series of directories,
separated by os.pathsep (; on Windows, : on Unix).
Directories given in JUPYTER_PATH are searched before other
locations.

Things like connection files, which are only useful for the lifetime of a
particular process, have a runtime directory.

On Linux and other free desktop platforms, these runtime files are stored in
$XDG_RUNTIME_DIR/jupyter by default. On other platforms, it’s a
runtime/ subdirectory of the user’s data directory (second row of the
table above).

An environment variable may also be used to set the runtime directory.